1. Field of th Invention
The present invention relates to a gas control valve assembly and, more particularly, to such a gas control valve assembly that can be controlled to turn on/off the supply of fuel gas, can also be controlled to regulate the flow rate of supplied fuel gas.
2. Description of the Related Art
A valve is a device which controls the flow of a liquid or gas through a pipe by opening and closing the passage. In a hot water heater or furnace, a gas valve may be used to control the supply of fuel gas by means of pressure difference. A gas valve of this kind comprises a valve flap and two pressure chambers at two sides of the valve flap. When the pressure of the two pressure chambers is in balance, a small flow rate of fuel gas passes out of the first pressure chamber to the gas nozzle for ignition by sparked discharged from a discharging electrode to produce an ignition flame. When the induction electrode detected the presence of the ignition flame, the gas inlet of the first pressure chamber is closed to lower the pressure of the first pressure chamber, causing the valve flap to change the position for enabling a big flow rate of fuel gas to pass out of the gas valve to the gas burner for burning by the ignition flame to produce a master flame for heating. This design of gas valve cannot regulate the flow rate of fuel gas passing to the gas burner. For controlling the flow rate of fuel gas, an external gas flow rate regulator shall be used.